It is now common for modern mobile telephones to include a camera for capturing stills and video, and a microphone for capturing sound recordings, either as a sound channel to a video recording or a separate sound recording.
Known devices, as well as recording primary data (e.g. a photograph or a video), also record metadata relating to the capture. For example, when capturing a photograph, many devices will store the current time and date, and coordinates of the physical location of the device when the photograph was captured.
In most cases, this metadata is a convenient feature which is useful to a consumer so that he can view and share his photographs (for example) based on where and when they were taken, without the need to make notes and organise the captured pictures manually. However, in some cases verifying that the time and place attached to a particular photograph is accurate may be critical.
News organisations often receive submitted photographs and videos from members of the public, but these organisations have to be careful to verify the authenticity of what they are being presented with—in particular that the photograph (for example) really was taken at the time and place claimed. In the past, even reputable news organisations have fallen victim to falsified submitted photographs and published them as genuine.
There are generally no safeguards against false attribution of time and place to a photograph on known devices. Even if a mechanism exists to ensure that the current GPS location of the device is stored with the photograph, and even if there is a mechanism to prevent later tampering with that location metadata, it is known that GPS transmissions can be “spoofed” by an external transmitter, to cause a GPS receiver to report an incorrect location.
It is an object of the present invention to provide means by which the integrity of metadata attached to primary data by a consumer electronic device may be verified with various levels of confidence.